Tower construction



H. O. HILL TOWER CONSTRUCTION Oct. 9, 1928. 1,687,449

Filed July 28, 1926 Patented Oct. 9, 1928.

UNITED-STA TES PATEN T OFFICE.

MANUFACTURING COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OFPENNSYLVANIA.

TOWER CONSTRUCTION.

Application filed July 28,

This invention relates to improvements in steel transmission towersemployed for supporting electric conducting wires or cables,

and it relates more particularly to that class of towers having crossarms from which suspended insulators strings for supporting theconductors are hung.

In use, electric conductors or circuits supported on steel transmisisontowers and poles are quite often subjected to interruptions in thecontinuity of the current due to arcs or flash-overs from the conductorsto the adjacent steel members of the structure, due to lightningdisturbances. These flash-overs usually disrupt the service and renderall users of the power without service until the damage to the circuitscan be repaired and the service restored,

Attempts have been made to eliminate or reduce arcing or flash-overs byspacing the conductors, wires, or Cables away from the cross-arm hangerbraces and other tower members, so that the air gaps between theconductors and the braces or other members will afiordsuificientresistance toprevent arcing. This necessitates the use of long crossarmsand very high structures and long strings of insulators, all of whichmaterially increase the cost of the transmission line and thus the costof the electric service.

The crossarms, hangers, and other parts entering into towerconstruction, adjacent to or relatively near the conductors, haveusually been formed of steel bars placed on edge or steel angle membershaving sharp edges or corners. This construction, embodying members ofthe character stated and positioned as described, provides one that'ispal?- ticularly liable to produce arcing or flashovers. I havediscovered that by forming the exposed surfaces of the said membersnearthe conductors without edges, sharp angles or corners, arcing orflash-overs at these points are practically eliminated.

Among the objects of my invent-ion are, to provide a tower constructionembodying members, disposed close to the conductors, having curved orrounded exposed surfaces, and a construction devoid of sharp edges,angles, and sharp corners; also, to provide a construction thateliminates or greatly reduces the liability of arcing from the conduc=tors to certain tower members, without the nemas =iid5 of large verticaland horiziintal 1926. Serial No. 125,420.

separation of the conductors and said members.

In the accompanying drawings, whichillustrate applications of myinvention:

Fig. 1 is an elevational view of a portion of a transmission towerembodying my invention Fig. 2, a horizontal sectional view taken on lineIIII of Fig. 1; r

i Fig. 3, a view similar to Fig. 2, taken on line IIIIII of Fig. 1;

Fig. 4, a detail plan view of a cross-arm constructed of tubularmembers;

Fig. 5, a detail plan view, partly broken away, of a tubular structuralmember that may be employed in the tower construction;

Fig. 6, a similar View of amodified form of member;

Fig. 7, a detail elevational view, partly broken away, of a structuralsteel member and its tubular protective covering;

Fig. 8, a view similar to Fig. 7, showing an irngle member and itsprotective covering; anc t Fig. 9, a sectional view, the section beingtaken on line IX-IX of Fig. 8.

Referring to the drawings, the tower structure, as illustrated, includesthe usual vertically extending corner diagonals t3 extending across thefour sides of the tower and Connected with the corner posts in the usualmanner.

Extending upwardly from the upper ends of the corner posts 5 are fourvertically extending angle members 7, said members constituting thecorner posts of the upper square portion of the tower. 8 designatescrossmembers or diagonals also entering into the construction of thesaid upper tower portion.

Disposed at the desired levels on the upper tower portion are aplurality of cross arms 9, 10 and 11. These cross-arms are secured tothe top portion of the tower, designated generally by the character A,and project from two faces or sides thereof in the usual manner.

Suspended from the outer ends of the respective crossarms are stringinsulators 12. Each of the said string insulators is designed to connectwith an electrical conductor, wire or cable 13.

The respective cross-arms 9 and 10 are preferably braced by hangermembers or han er braces 14 and 14 having their inner ends connectedwith. the comet members '7 and posts 5 and the cross extendingdownwardly and outwardly therefrom. The upper cross-arm 11 is reinforcedby hanger braces 15 extending downwardly from the top tower members 16.

Located immediately under the upper cross-arn'i 11 and on two faces ofthe upper portion A of the tower and between the said cross-arm and theliangenbraces 146, I provide protective plate member 17. These platemembers are secured to the members 7 and preferably have rounded ends oredges 17 The function of the said protective plates is to prevent arcingor flash-overs from the conductors to that portion of the tower coveredby said plates. 18 designate similar protective plate members disposedon two sides of the tower structure just below the lower cross-arm 9 andrelatively close to the lower insulator strings 12 and the lowerconductors 13.

In order to prevent arcing between the conductor lines and the anglemembers entering into the formation of the respective crossarms, saidmembers are provided with protective members 19 having rounded exposedsurfaces. These protective members 19 are particularly shown by Figs. 8and 9,- Fig. 9 shows rivets 19 for securing the member 19 to the anglemember of the cross-arm. It is, or course, evident that, so long as theprotective member 19 has a curved surface, the cross-section thereof mayvary. For we ample, it may be either circular, as in the form of Fig. 7,or semi-circular, as shown by Fig. 9; or the protective covering may bespherical. The said members may be made of sheet material or of wiremesh.

The hanger braces 14 are usually bars and, if this is the case, Ipreferably employ a circular protecting covering member 20. Such amember will afford protection to the said hanger members from theconductors carried by the upper cross arm 11 and the intermediatecross-arm 10.

Fig. 4 shows a cross-arm formed of tubular members 21, said members 21being shown also in the enlarged view, Fig. 5. A crossarm could also beconstructed of members 22 shown by Fig. 6. anger braces might also takethe form of members 21 or 22.

My invention contemplates the employment of curved surfaces, either inthe form of coverings for angular members or bars, from which the towercross-arms and other tower members relatively close thereto are formed,or the employment of such surfaces in the formation of the said arms perse and the members relatively close thereto. It further contemplates theuse of protective plate members, as shown and described.

lVhat I claim is:

1. In a structural tower, the combination with a suspended insulatorstring carrying a transmission wire, of an upper body portion formed ofangular members, a cross-arm formed of angular members, a metallicprotector plate on the body adjacent the crossarm, and metallicprotector elements for the cross-arm members having curved surfaces.

2. In a structural tower, the combination with a suspended insulatorstring carrying a transmission wire, of an upper body portion formed ofangular members, an upper, a lower and an intermediate crossarm formedof angular members, a metallic protector plate on the body adjacent theupper crossarm, a similar plate adjacent the lower crossarm, andmetallic protector elements having curved surfaces for the cross-armmembers.

3. In a structural tower, the combination with a suspended insulatorstring carrying a tral'ismission wire, of a plurality of cross armsarranged one above the other, a protective metallic plate covering forthe body of: the tower located between two adjacent cross arms, andmetallic protector elements having curved surfaces for the cross-armmembers.

In testimony whereof I affix my signature.

HAROLD O. HILL.

